Chef and GemStones

Vinay and his friend Chef wants to get the gem stone to protect it from getting into evil hands. Arjuna(a very sleepy fellow) being the guard of the gem stone is very greedy and has a special bag, into which he can add one gold coin at a time or can remove the last gold coin he added. Arjuna will sleep, once he will have the enough number of gold coins worth amount X. To help Vinay, Chef has given